KR20190037233A - Artificial mitral valve containing an annulus-ventricular coupling mechanism - Google Patents

Abstract

The artificial mitral valve comprises a flexible frame comprising an annular base and a pair of diametrically opposed struts extending downward from the annular base, an annulus having a natural mitral valve removed, A sewing ring mounted to the annular base for securing a prosthetic mitral valve, a pair of leaflets mounted on the annular base and diametrically opposed pair of struts, And a pair of coupling sutures configured to extend across the left ventricle from below the pair of diametrically opposed struts and to secure the prosthetic mitral valve to the papillary muscle.

Description

Artificial mitral valve containing an annulus-ventricular coupling mechanism

This patent application was filed on July 6, 2016 by The Methodist Hospital and Matthew Scott Jackson et al., Pending U.S. Provisional Patent Application No. 62 / 358,636 (Attorney Docket No. METHODIST-20 PROV), the patent application of which is incorporated by reference in this application.

The present invention relates generally to surgical methods and devices, and more particularly to surgical methods and devices for enhancing mitral valve function.

The human heart has four chambers (right atrium, right ventricle, left atrium and left ventricle) and four valves (a tricuspid valve located between the right atrium and right ventricle, a pulmonary valve located at the exit of the right ventricle, a mitral valve located between the left atrium and left ventricle, And an aortic valve located at the exit of the left ventricle). Please refer to Fig. The right atrium receives oxygen-depleted blood from the body, the right ventricle pumps oxygenated blood to the lungs for oxygen supply, the left atrium receives oxygenated blood from the lungs, and the left ventricle receives oxygenated blood into the body Pumped.

As described above, the mitral valve is positioned between the left atrium and the left ventricle. Normal functioning mitral valves allow blood to flow from the left atrium to the left ventricle when the left ventricle expands (ie during diastole), and prevents reverse flow of blood from the left ventricle to the left atrium when the left ventricle contracts (ie during systole) do.

The mitral valve is generally characterized by an annulus attached to the surrounding tissue, a leaflet that opens and closes during valve function, and a chordae tendineae that connects the leaflet to the papillary muscle extending from the lower ventricular wall. Referring to FIG. 2, the mitral valve in the open position as the left ventricle expands (i.e. during diastole) is shown. Figure 3 shows the mitral valve in the closed position as the left ventricle contracts (i.e. during systole).

In some cases, the mitral valve is not functioning properly and reflux may occur. This backflow reduces the pumping efficiency of the heart. For example, mitral regurgitation is common in patients with heart failure. Mitral regurgitation in patients with heart failure is usually caused by changes in the geometric configuration of the left ventricle, papillary muscle, and mitral annulus. These anatomical structural changes often lead to incomplete coaptation of the mitral leaflet during systole, resulting in mitral regurgitation.

If the mitral regurgitation is caused by a change in the geometry of the left ventricle, papillary muscle, and mitral annulus, mitral valve regurgitation generally causes the mitral annulus to wrinkle, correcting the shape of the enlarged annulus, Thereby restoring the geometric structure. In particular, current surgical operations for mitral valve repair generally require surgical opening of the heart and then fixation of the suture, or more generally suture, to the inner surface of the annulus in combination with the support ring, It is necessary to restore the membrane annulus and use this structure to draw the annulus in its proper configuration, such as a purse string, to improve the leaflet connection and reduce mitral regurgitation. This mitral valve repair method, commonly referred to as "annuloplasty", effectively reduces mitral regurgitation in patients with heart failure. This, in turn, reduces symptoms associated with heart failure, improves patient quality of life, and prolongs patient longevity.

Unfortunately, such mitral valve surgery is not effective in all circumstances, and in some situations, it may be necessary to replace the natural mitral valve with an artificial mitral valve. In this situation, the artificial mitral valve includes a rigid annulus sized to be generally received in the seat of the natural mitral valve, and a plurality of leaflets mounted in the rigid annulus. The rigid annulus includes a sawing ring so that the artificial mitral valve can be stowed in place in the seat of the natural mitral valve. However, the artificial mitral valve does not normally have a rigid annulus or leaflet anchored to the papillary muscle of the left ventricle, so it can not accurately mimic the action of the natural mitral valve (the leaflet is anchored to the papillary muscle by the chisak). In particular, the natural mitral annulus is flexible with an anterior-posterior motion. The natural annulus to the papillary muscles of the mitral leaflets - Ventricular coupling (by chord) prevents ventricular dilatation, preserves cardiac size and shape, and maintains cardiac function.

Therefore, there is a need for a new and improved artificial mitral valve that mimics the action of the natural mitral valve more accurately.

The present invention includes the provision and use of new and improved artificial mitral membranes that more accurately mimic the action of the original mitral valve. More particularly, the new and improved artificial mitral valve includes a single flexible frame comprising an annular base and a pair of diametrically opposed struts extending downwardly from the annular base do. A sewing ring is mounted to the annular base to secure the annular base to the seat of the natural mitral valve. Two leaflets are mounted on the annulus base and a pair of struts opposite in radial direction. A pair of coupling sutures extend from the sawing ring, across the left ventricle to the papillary muscle, below the diametrically opposed pair of struts. In this way, by connecting a new and improved artificial mitral valve to both the annulus and the papillary muscle of the natural mitral valve, the artificial mitral valve mimics the action of the natural mitral valve more accurately.

In one preferred form of the invention, there is provided an artificial mitral valve membrane,

A flexible frame including an annular base and a pair of struts extending downwardly from the annular base and diametrically opposed,

A sawing ring mounted on the annular base for securing the artificial mitral valve to the annulus with the natural mitral valve removed,

A pair of leaflets mounted on said annular base and said pair of struts opposite in diametrical direction, and

And a pair of coupling sutures configured to extend across the left ventricle from below the pair of struts facing diametrically opposite the left ventricle and to secure the artificial mitral valve to the papillary muscle.

In another preferred form of the present invention, a method of improving mitral valve function is provided,

A step of providing an artificial mitral valve membrane;

A flexible frame including an annular base and a pair of struts extending downwardly from the annular base and diametrically opposed,

A sawing ring mounted to the annular base for securing the artificial mitral valve to the annulus with the natural mitral valve removed,

A pair of leaflets mounted on said annular base and said pair of struts opposite in diametrical direction, and

A pair of coupling sutures configured to extend across the left ventricle from below said pair of struts opposite diametrically opposed to said artificial ring and to secure said artificial mitral valve to the papillary muscles,

A step for removing the natural mitral valve,

Fixing the pair of coupling sutures to the papillary muscles,

Fixing the sawing ring to the sheet of the natural mitral valve membrane,

Imparting a tension to the pair of coupling sutures to set a tension between the annular base and the papillary muscles;

And fixing the pair of coupling sutures to the sawing ring.

1 is a schematic view of a human heart.
Figures 2 and 3 are schematic views of a mitral valve.
4 to 6 are schematic views showing a new and improved artificial mitral valve formed according to the present invention;
Figures 7 to 20 are schematic diagrams showing additional structural details of the new and improved artificial mitral valve of Figures 4 to 6;
21 (a) is a bottom view of the artificial mitral valve of Figs. 4 to 6 showing a manifold and a leaflet attached to a pair of diametrically opposed struts; the front and rear leaflets are shown in intermediate configuration;
Fig. 21 (b) is a side view of the artificial mitral valve of Figs. 4 to 6 showing the arch of the anterior portion of the annular base; Fig.
Fig. 21 (c) is a bottom view of the artificial mitral valve of Figs. 4 to 6, and the front and rear leaflets are shown in an open configuration similar to the expander.
Figs. 21 (d) and 21 (e) are in vitro images of the leaflets of the artificial mitral valve membranes of Figs. 4 to 6 and are shown as closed configurations (systolic coaptations) taken respectively in the vertex and left atrial views.
Figures 21 (f) and 21 (g) are in vitro images of the anterior and posterior leaflets of the prosthetic mitral membranes of Figures 4 to 6 and are shown as open configurations (dilator orifices) taken respectively at the apex and left atrium views.
Figs. 22, 23, 24A to 24D, 25A to 25C, and 26 to 29 are cross-sectional views of FIGS. 6 shows a schematic diagram of a new and improved artificial mitral valve.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will become more fully disclosed or become apparent by the following detailed description of the presently preferred embodiments of the invention taken in conjunction with the accompanying drawings, do.

The present invention includes the provision and use of a new and improved artificial mitral valve (5) that more accurately mimics the action of the natural mitral valve.

4 to 13, a new and improved artificial mitral valve 5 includes a pair of diametrically opposed pairs extending downwardly from the annular base 15 and the annular base 15 Includes a single flexible frame (10) comprising a strut (20). The front leaflet 25 and the rear leaflet 30 are mounted on the annular base 15 and a pair of diametrically opposed struts 20. The sawing ring 35 is mounted to the annular base 15 such that the annular base can be secured to the seat of the natural mitral valve. The pair of coupling sutures extend across the left ventricle from the sawing ring 35 to below the pair of diametrically opposed struts 20 so as to secure the artificial mitral valve 5 to the papillary muscles. In this way, by connecting a new and improved artificial mitral valve to both the annulus and the papillary muscle of the natural mitral valve, the artificial mitral valve mimics the action of the natural mitral valve more accurately.

7-13, the artificial mitral valve 5 includes a pair of diametrically opposed pairs extending downwardly from the annular base 15 and the annular base 15, And a flexible frame (10) comprising a strut (20).

The annular base 15 includes a front portion 16 and a rear portion 17. Each of the diametrically opposed pair of struts includes a first leg 22 connected to the front portion 16 at an upper end of the first leg 22 and a second leg 22 extending from an upper end of the second leg 24 17 which is connected to the second leg 24. The lower ends of the first leg 22 and the second leg 24 are connected together at a hinge point 23.

In one preferred form of the invention, the annulus base 15 and the diametrically opposed pair of struts 20 preferably have a single length of high elasticity, such as shape memory alloy wire (e.g. Nitinol) As shown in Fig. In this configuration, the annular base 15 of the flexible frame 10 and the diametrically opposed struts 20 are positioned in the same direction as needed as the peripheral cardiac anatomy repeats from the divergent to the systolic and from the systolic to the diastolic It can be flexible. In particular, in the present invention, the anterior portion 16 and the posterior portion 17 of the annular base 15 can be flexible with respect to one another during cardiac cycling, so that they can better conform to the surrounding anatomy. In this regard, the forward portion 16 and the rear portion 17 of the annular base 15 are connected to the radially opposed struts 20 (the front portion 16 of the annular base 15 and the rear portion 17 (Which acts as a hinge mechanism between the annular base 15 and the annular base 15). Further, in the present invention, the lower ends (i.e., the hinge points 23) of the struts 20 opposed in the radial direction are freely moved toward and away from each other during cardiac cycling. It will be appreciated that the various elements of the flexible frame 10 are sized to mimic the natural mitral valve. For example, reference is made to Fig. 14 which provides an exemplary size dimension.

4 to 9 and 15 to 20, a front leaflet 25 and a rear leaflet 30 are mounted on an annular base 15 and a pair of diametrically opposed struts 20 . 19) to a forward portion 16 of the annular base 15 and a pair of diametrically opposed struts 20 in a preferred form of the present invention, And the rear leaflets 30 are sealed along the sealing line 27 (Fig. 20) to the rear portion 17 of the annular base 15 and the pair of struts 20 opposed in the radial direction . Each leaflet follows the curvature of the flexible frame 10 at the point of connection of the leaflet to the annular base 15 and a pair of diametrically opposed struts 20. In this manner, as shown in Figures 21 (a) - 21 (g), the leaflets 25,30 can be opened during the diastole and closed during the systole. In one preferred form of the invention, the leaflets 25, 30 are asymmetric so as to mimic the discharge flow of the natural mitral valve, i. E. The front leaflet 25 preferably produces a concave tunnel to provide an optimal drainage .

In another aspect of the invention, the two valve leaflets may be formed into tubes, rather than two pieces.

4 to 9, the sealing or sawing ring 35 is mounted to the annular base 15 such that the annular base can be secured to the seat of the natural mitral valve.

A pair of coupling sutures 40 and 45 (Figs. 4-6) extend from the sawing ring 35 across the left ventricle to the papillary muscle, below the diametrically opposed pair of struts 20. See FIGS. 22 and 23. FIG. Thus, in the present invention, the chordae of the natural mitral membranes are "held" by the provision of coupling sutures 40 and 45, providing good valve function and preventing "ballooning" of the left ventricle. However, in the new and improved artificial mitral valve 5, "chord" (ie, coupling sutures 40, 45) extend between the annular base 15 of the flexible frame 10 and the papillary muscle, Note that it is not fixed directly to the leaflets 25, If desired, suture channels 50, 55 (e.g., tubular structures) may be provided along each of the diametrically opposed struts 20 to the coupling sutures 40, 45 through assembly . Also, if necessary, the coupling sutures 40, 45 may pass along some or all of the perimeter of the flexible frame 10, for example, as shown in Fig. To help the surgeon in fixing the coupling sutures 40, 45 to the papillary muscles, pledgets 60, 65 may be mounted to the lower ends of the coupling sutures 40, 45. As will be described in greater detail below, the coupling sutures 40 and 45 can be tensioned and fixed in length (e.g., with a knot, etc.).

Referring to Figs. 24A to 24D, 25A to 25C, and 26 to 29 in use, the surgeon removes the natural mitral valve, The lower ends of the coupling sutures 40 and 45 are secured to the papillary muscles (e.g., with flanges 60 and 65) and the shaping ring 35 is positioned on the seat of the natural mitral valve, ) Is sealed to the sheet of the natural mitral valve. The surgeon then applies tension to the upper ends of the coupling sutures 40, 45 to establish a tension between the annulus base 15 of the artificial mitral valve 5 and the papillary muscle. Preferably, the tension is applied by filling the left ventricle with saline while the leaflets 25, 30 are closed, which results in a dynamic response of the coupling sutures 40, 45 when the left ventricle is fully inflated Thereby enabling tensioning. When the tension between the annular base 15 and the papillary muscle is appropriately set, the coupling sutures 40 and 45 are folded together by, for example, binding a suture with a knot 70 of the same height as the sawing ring 35 Is fixed to the sawing ring (35).

Artificial mitral valve mimics the action of the natural mitral valve by connecting the artificial mitral valve to the sheet of natural mitral valve (i.e., by the sighting ring 35) and the papillary muscle (i.e., by the coupling sutures 40, 45) . The new and improved artificial mitral valve is a saddle-shaped, physiologically dynamic flexible annulus (an annular base 15 and a sawing ring 35), an annular base (via coupling sutures 40 and 45) Ventricular-annulus coupling from the pawl ring 15 and the sawing ring 35 and the papillary muscles 85 and 90 and the asymmetric rear and frontal valve leaflet designs such as the asymmetric posterior leaflet 30 and the frontal leaflet 25 )). The ventricular flow is more efficient when the dilator 105 (i.e., when the left ventricle is expanded and blood flows from the left atrium to the left ventricle) and the systolic 110 (i.e., when the left ventricle contracts and blood is prevented from flowing backward from the left ventricle to the left atrium) And exhibits efficient physiological hemodynamics without interfering with the left ventricular outflow track 115.

Variations of the preferred embodiment

It should be understood that many additional changes in the details, materials, steps, and arrangements of the parts described and illustrated in this application to explain the nature of the invention may be made by those skilled in the art, while remaining within the principles and scope of the invention do.

Claims (21)

A flexible frame comprising an annular base and a pair of diametrically opposed struts extending downwardly from the annular base,
A sewing ring mounted on the annular base for securing an artificial mitral valve to an annulus having a natural mitral valve removed,
A pair of leaflets mounted on said annulus base and said pair of struts opposite in diametrical direction,
An artificial mitral valve comprising a pair of coupling sutures configured to extend across the left ventricle from below said pair of struts opposite diametrically opposite said artificial mitral valve to fix said artificial mitral valve to said papillary muscle. The method according to claim 1,
Wherein the annular base includes a front portion and a rear portion. The method according to claim 1,
Wherein each of said diametrically opposed pair of struts comprises a first leg and a second leg joined together at a hinge point. The method of claim 3,
The first leg of each of the diametrically opposed pair of struts is mounted to the front portion of the annular base and each second leg of the diametrically opposed pair of struts is attached to the annulus, Artificial mitral valve membrane mounted on the back of the base. The method according to claim 1,
Wherein the frame comprises a shape memory alloy wire. The method according to claim 1,
Wherein the pair of leaflets are mounted on the annular base and the pair of struts opposite to each other in the radial direction by a suture yarn. The method according to claim 1,
Wherein the pair of leaflets is asymmetric. The method according to claim 1,
Further comprising a pair of suture channels mounted to said flexible frame to receive said pair of coupling sutures. The method according to claim 1,
Further comprising a pair of pledgets for securing said pair of coupling sutures to said papillary muscles. A step of providing an artificial mitral valve membrane;
A flexible frame including an annular base and a pair of struts extending downwardly from the annular base and diametrically opposed,
A sawing ring mounted to the annular base for securing the artificial mitral valve to the annulus with the natural mitral valve removed,
A pair of leaflets mounted on said annular base and said pair of struts opposite in diametrical direction, and
A pair of coupling sutures configured to extend across the left ventricle from below said pair of struts opposite diametrically opposed to said artificial ring and to secure said artificial mitral valve to the papillary muscles,
A step for removing the natural mitral valve,
Fixing the pair of coupling sutures to the papillary muscles,
Fixing the sawing ring to the sheet of the natural mitral valve membrane,
Imparting a tension to the pair of coupling sutures to set a tension between the annular base and the papillary muscles;
And securing the pair of coupling sutures to the shaping ring. 11. The method of claim 10,
Wherein the pair of coupling sutures are secured to the papillary muscle using a pair of flats. 11. The method of claim 10,
And fixing the sawing ring to the seat of the natural mitral valve membrane using a suture. 11. The method of claim 10,
Wherein the tension is applied by closing the pair of leaflets and filling the left ventricle with saline. 11. The method of claim 10,
Wherein the coupling suture is secured to the sawing ring by binding the suture with a knot. 11. The method of claim 10,
Wherein the annular base includes a front portion and a rear portion. 11. The method of claim 10,
Each of said pair of struts opposing in the radial direction comprises a first leg and a second leg joined together at a hinge point. 17. The method of claim 16,
The first leg of each of the diametrically opposed pair of struts is mounted to the front portion of the annular base and each second leg of the diametrically opposed pair of struts is attached to the annulus, And is mounted to the rear portion of the base. 11. The method of claim 10,
Wherein the frame comprises a shape memory alloy wire. 11. The method of claim 10,
Wherein the pair of leaflets is mounted to the annular base and the pair of struts opposite radially by a suture. 11. The method of claim 10,
Wherein the pair of leaflets is asymmetric. 11. The method of claim 10,
Further comprising a pair of suture channels mounted to the flexible frame to receive the pair of coupling sutures.

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